Tuesday, November 13, 2012


1.   Highest capacity vector is
a) Cosmid
b) YAC
c) Yeast integrative vector
d) Bacteriophage vector
Ans: b
  • Cosmid: A plasmid with a cos site of lambda phage.Insert size: 30-45 kb
  • YAC: yeast artificial chromosome. Insert size: 1 Mb
  • Bacteriophage vectors: refers to lambda and M13 phage vectors
  • Lambda phage vectors: Insert size: 8-23 kb
  • M13 vectors used for obtaining single stranded copies of cloned DNA that are suited for DNA sequencing
  • BAC: Bacterial Artificial Chromosome. Insert size: 300 kb
2.   The C value denotes the total number of DNA in a
        a) Diploid
        b) Haploid
        c) Aneuploid
        d) Polyploid
  • C value: Haploid DNA content of an organism or the amount of DNA in haploid nuclei like a gamete.
  • C value paradox: refers to the phenomenon that huge genomic content has nothing to do with the complexity of an organism.For eg: Protists has genome size much larger than humans.
3. Cdc mutants are useful for the study of 
a) Chromosome breakpoint
b) Apoptopsis
c) Various stages of Cell cycle
d) Homeodomain 
 Ans: c  cdc refers to cell division cycle

4.  RNA is very much susceptible to hydrolysis in alkali because
a) It contains Uracil residues in its structure
b) Its 2’ OH groove participate in intramolecular cleavage of phosphodiester backbone
c) Cleavage occurs in the glycosilic bonds of purine bases
d)Cleavage occurs in the glycosilic bonds of pyrimidine bases
  • Because of the presence of 2’ OH group in the ribose sugar
  • DNA is more stable than RNA because of the presence of H at 2’ position in DNA rather than OH in RNA.
5. Which one of the following is not a requirement of a PCR reaction?
a) DNA template
b) NTPs
c) MgCl2
d) Taq polymerase
Here the best option is MgCl2 even though it is required for DNA polymerase activity. (It can be avoided)

6. The heterozygosity of any locus can be ascertained by
 a) SNPs
b) RFLPs
c) FISH analysis
d) Either RFLP analysis or SNP
Ans: d
  • SNP: single nucleotide polymorphism refers to the variation in the lengths of some DNA btw individuals due to single base changes
          Application: used in DNA finger printing
  • RFLP: restriction fragment length polymorphism: refers to the variation in the restriction fragment length between individuals of a species.
  •  FISH: florescence insitu hybridization: hybridizing fluorescently labelled DNA probes on to human chromosome preparations allows genes to be mapped directly to their chromosomal locations.
7.  Hormone pairs requires for a callus to differentiate are
 a) Auxin and Cytokinin
b) Auxin and Gibberellin
c) Cytokinin and Gibberellin
d) Ethylene and Gibberllin 
Ans: a
Auxin induces rooting whereas cytokinins promote shooting if supplied in optimum ratio.

8. Embryo rescue is a useful technique to 
 a) Grow /generate hybrids between different plant species
 b) Complete the growth of embryos susceptible to defects in seed development
 c) Break the dormancy of seeds
 d) All of the above

9. Antibody diversity is generated by           
a) protein splicing
b) somatic mutations
c) allelic exclusion
d) interchromosomal recombination          
   Ans: b
  • Somatic mutation: a mechanism by which point mutations are introduced into rearranged immunoglobulin variable region genes during activation and proliferation of B cells. It contributes significantly to antibody diversity.
  • Allelic exclusion: a process that permits the expression of only one of the allelic forms of a gene. It contributes to specificity of IgGs
10. The precursor for penicillin-G biosynthesis during fermentation process is            
a)Phenylacetic acid
b)Acetic acid
c)Phenoxy acetic acid
d)None of the above

11.Plastome is                
a)Plasmalemma protein
b)A type of plasmid
c)An organellar genome
d)None of the above
Ans: plastome: Genetic material of plastid like Chloroplast

12. Which of the following process require energy
a) ligation
b) restriction digestion
c) hybridization
d) transformation
Ligation: sealing of single stranded nicks or breaks by ligase enzyme. The process requires ATP and NADP+.

13) Enhanced axillary branching for multiple shoot production is promoted by               
b)Abscisic acid
c)BA (Benzyl adenine)
d)Gibberellic acid
2,4-D is an auxin and auxin is responsible for sustaining apical dominance there by promoting axillary branching

14.  Viral replication within cells is inhibited by             
c)IFN alpha
d)TNF alpha
Interferons: are antiviral agents (proteins) secreted by virus infected cells and induces a virus resistant state to the surrounding cells by inhibiting its replication.

15.  In the course of cell cycle, the level of the protein cyclin abruptly falls during             
a) G1phase
b) G2 phase
c) S phase
d) M phase

16. Protein binding regions of DNA are identified by one of the following techniques
a) Finger printing
b) Foot printing
c) Southern blotting
d) Western blotting
  Ans: (b) Foot Printing
  • Foot Printing: The identification of a protein-binding site on a DNA molecule by determining which phosphodiester bonds are protected from cleavage by DNase I.
  • Southern Blotting: The technique used for identifying specific DNA fragment using labelled probe.
17.Si RNA (s) interfere at
a) Transcriptional level
b) Post -transcriptional level
c) DNA replication level
d)Translational level
Ans: (b) Post -transcriptional level

18. Plant secondary metabolites
a) Help to increase the growth rate of plant
b) Help in plant reproduction processes
c) Provide defence mechanisms against microbial attack
d) Make the plant susceptible to unfavourable conditions
Ans: (c) Provide defence mechanisms against microbial attack

19. Mobile genetic elements present in human genome are
R) P elements
S) IS elements
(a) Q, R (b) P, Q  (c) P, R (d) Q, S
Ans: (b) P, Q

20. Meristems escape virus invasion because
a)Vascular system is absent in the meristem
b) of low metabolic activity in the meristem
c) of low endogenous auxin level
d) the virus inactivating system has low activity in the meristem
Ans: b) of low metabolic activity in the meristem

21. The enzyme that can be used in 5’end labeling of DNA are
P) Alkaline phosphatase
Q) DNA ligase
R) Terminal transferase
S) Polynucleotide kinase
(a) P, S (b) R, Q (c) P, R (d) R, S
Ans: (a) P, S

22. Identify the natural plant growth regulators from the following list
 P) Zeatin
Q) Benzylamino purine (BAP)
R) Indole Acetic Acid (IAA)
S)  2,4-Dichlorophenoxyacetic acid (2,4-D)
(a)P, Q (b) Q, S (c) P, R(d) R,S
Ans: c) P, R

23. Cells of meristemoid are best described as
a) differentiated and non dividing
b) Dedifferentiated and dividing
c) differentiated and dividing
d) dedifferentiated and non dividing
Ans: c) differentiated and dividing

24. Ultra filtration process cannot be used for
a)Fractionation of Proteins
c) Harvesting of cells
d)Selective removal of solvents
Ans: c) Harvesting of cells

25. The number of replicons in a typical mammalian cell is
a) 40-200
b) 400
c) 1000-2000
d) 50000-100000
Ans: a) 40-200

26. What product will result from complete hydrolysis of soluble dextran
a) Sucrose only
b) Fructose only
c) Glucose &Fructose only
d) Glucose only
Ans: d) Glucose only

27. The mobility of DNA in agarose gel electrophoresis is solely based on its
a) Charge
b) Conformation
c) Size
d) None of these
Ans: c) Size

28. Which of the following fluorescent probes is used to monitor the progress of amplification of Real Time PCR?
a) SYBR Green
c) Cyan Blue
d) Rhodamine
Ans: b) FITC

29. Expression of which of the following reporter genes does not require addition of specific substrate for detection
a) Luciferase
b) β- Glucuronidase
c) β-Glucosidase
d) Green Fluorescent Protein (GFP)
        Ans: a) Luciferase
30. Zinc fingers are characteristic of
(a) Blood clotting Proteins
(b) RNA Chaperones
(c) DNA binding proteins
(d) Lysosomal hydrolyses
Ans: DNA binding proteins
  • Chaperons: proteins that assist in proper folding of proteins.
31. Multiplication of genetically identical copies of a cultivar by asexual reproduction is known as
(a) aclonal propagation
(b) clonal propagaation
(c) polyclonal propagation
(d) vegetative propagation
Ans: clonal propagaation

32. Parthenogenetic embryos in plant are those are formed by
(a) unfertilized eggs
(b) fertilized eggs
(c) male gametophyte
(d) sporophytic cells
Ans: unfertilized eggs
  • Parthenogenesis: The development of an individual from an egg without fertilization.
33. Which one of the following is the growth factor used for growth of tissues and organs in plant tissue culture?
(a) Cytokinin
(b) Cysteine
(c) Cytidylate
(d) Cyclic AMP
Ans: Cytokinin
  • Cysteine :Sulphur containing amino acid
  • Cytidylate: an enzyme with kinase activity
  • Cyclic AMP: second messenger in intracellular signal transduction
34. Which of the following techniques is best suited for immobilizing an affinity ligand?
(a) Physical adsorption
(b) Gel entrapment
(c) Cross-linking with a polymer
(d) Covalent linkage to a spacer arm
Ans: Covalent linkage to a spacer arm                                                   

 35.  To be a cloning vector, a plasmid does NOT require
a) an origin of replication
b) a restriction site
c) an antibiotic resistance marker
d) to have a high copy number
Ans: d) to have a high copy number

Properties of a Cloning Vector
  • Should be able to replicate autonomously
  • Easy to transform
  • Should have suitable marker
  • Unique restriction sites
  • For expression vector, control elements like promoter, operator etc should be there.
36. Enzyme papain is used with success to
a) increase in meat production
b) leaven bread
c) ripen papaya fruit
d) tenderize meat
Ans: d) tenderize meat
  • Source: papaya fruit
37. For protoplast fusion to be successful in plant cells
a) fusion agents other than polyethylene glycol should be used
b) cellwall of the two strains of cells should be compatible
c) DNA between the two cells should be compatible
d) osmolarity of the medium is not important
Ans: DNA between the two cells should be compatible

38. In animal cell culture, the addition of serum to media is essential for providing
a) amino acids for protein synthesis
b) nucleotides for DNA synthesis
c) growth factors
d) All of the above
Ans: All of the above

39. Which one of the following reactions is used for the purpose of recycling enzymes in bioprocesses?
a) isomerisation
b) immobilisation
c) phosphorylation
d) polymerisation
Ans: Immobilisation
  • Technique used for the fixation of enzymes or cells on to solid supports
  • Advantage: reuse of enzyme for many reactions
  • Methods of enzyme immobilization:-adsorption, covalent bonding, entrapment, membrane confinement

------------------------------------------ Best Wishes: Dr.Ehab Aboueladab, Tel:01007834123 Email:ehab10f@gmail.com,ehababoueladab@yahoo.com ------------------------------------------
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